(19)

(11)

EP 0 327 575 A1

(12)

(43) Date of publication: 16.08.1989 Bulletin 1989/33 (21) Application number: 87907289.0 (22) Date of filing: 26.10.1987

(51) International Patent Classification (IPC):  E21B 4/ 14( . ) E21B 21/ 12( . ) (86) International application number: PCT/AU1987/000362 (87) International publication number: WO 1988/003220 (05.05.1988 Gazette 1988/10)

(84) Designated Contracting States: AT BE CH DE FR IT LI LU NL SE (30) Priority: 24.10.1986 AU 19860008685 (71) Applicant: LISTER, William Moorooka, QLD 4105 (AU)	(72) Inventor: LISTER, William Moorooka, QLD 4105 (AU) (74) Representative: Hands, Horace Geoffrey, et al  LEWIS W. GOOLD & CO. Whitehall Chambers 23, Colmore Row Birmingham B3 2BL Birmingham B3 2BL (GB)